wreq-js Documentation

getProfiles()

Get a list of all available browser profile labels.

Signature

function getProfiles(): BrowserProfile[]

Returns

Array of profile names that can be used with the browser option.

Example

import { getProfiles } from 'wreq-js';

const profiles = getProfiles();
console.log(profiles);
// Example output: ['chrome_142', 'firefox_139', 'safari_18', ...]

Using a random profile

Picking from getProfiles() directly mixes years-old versions with current ones and leaves the OS to chance, which produces fingerprints no real browser sends. Use randomProfile() instead.

getOperatingSystems()

Get a list of all available operating systems for emulation.

Signature

function getOperatingSystems(): EmulationOS[]

Returns

Array of OS names that can be used with the os option.

Example

import { getOperatingSystems } from 'wreq-js';

const systems = getOperatingSystems();
console.log(systems);
// Example output: ['windows', 'macos', 'linux', 'android', 'ios']

Combining browser and OS

import { fetch, getProfiles, getOperatingSystems } from 'wreq-js';

// Chrome on Windows
const response = await fetch('https://example.com', {
  browser: 'chrome_142',
  os: 'windows',
});

// Safari on iOS
const mobileResponse = await fetch('https://example.com', {
  browser: 'safari_18',
  os: 'ios',
});

resolveProfile()

Resolve a browser family alias to the concrete profile it points at.

Signature

function resolveProfile(browser: BrowserProfile | BrowserAlias): BrowserProfile

Returns

The concrete profile. Concrete profiles pass through unchanged, so this is safe to call on any value accepted by the browser option.

Example

import { resolveProfile } from 'wreq-js';

resolveProfile('firefox');     // 'firefox_149'
resolveProfile('firefox_143'); // 'firefox_143'

An alias resolves against the profile set shipped with your installed version of wreq-js, so the result moves when you upgrade. Log it when you need to know which fingerprint a given run actually used.

randomProfile()

Pick a random browser profile together with an operating system that browser actually ships on.

Signature

function randomProfile(options?: RandomProfileOptions): RandomProfile

interface RandomProfileOptions {
  families?: BrowserAlias[]; // default: ['chrome', 'edge', 'firefox', 'opera', 'safari']
  latest?: number;           // newest profiles per family to choose from, default 2
  os?: EmulationOS[];        // default: ['windows', 'macos', 'linux']
  random?: () => number;     // default: Math.random
}

interface RandomProfile {
  browser: BrowserProfile;
  os: EmulationOS;
}

Returns

A { browser, os } pair to spread into createSession(), createTransport() or fetch() options. A family is chosen first, then one of its newest latest profiles, then one of the operating systems it runs on, each uniformly at random. Picks are not weighted by market share. Each family is only paired with platforms it really ships on:

Family	Operating systems
`chrome`, `edge`, `firefox`	windows, macos, linux, android
`opera`	windows, macos
`firefox_private`	windows, macos, linux
`safari`	macos
`safari_ios`, `safari_ipad`	ios
`firefox_android`, `okhttp`	android

Chrome, Edge and Firefox are never paired with iOS: on iOS they use WebKit’s network stack, so their own TLS fingerprint with an iOS User-Agent is a combination no real browser produces.

Example

import { createSession, randomProfile } from 'wreq-js';

// One pick per session
const session = await createSession({ ...randomProfile() });

// Newest Chrome or Safari, phones only
const mobile = randomProfile({
  families: ['chrome', 'safari_ios'],
  os: ['android', 'ios'],
  latest: 1,
});

Keep a pick for the whole session. A fingerprint that changes between requests on the same cookies or IP stands out more than a fixed one.

Throws RequestError for an unknown family or OS, a latest that is not a positive integer, or options that leave no family with an allowed OS (such as safari with only windows).

getEmulationHeaders()

Get the headers a browser profile injects into every request, without sending one.

Signature

function getEmulationHeaders(browser?: BrowserProfile, os?: EmulationOS): Headers

Both arguments default to the same profile and OS as fetch.

Returns

A Headers instance holding the profile’s headers, in the profile’s own order and casing. Transport-level headers are not included: Host, Connection, Content-Length, and Accept-Encoding are added per request rather than by the emulation profile.

Example

import { getEmulationHeaders } from 'wreq-js';

const defaults = getEmulationHeaders('firefox_147');
console.log(defaults.get('user-agent'));
// Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:147.0) Gecko/20100101 Firefox/147.0

Reusing a profile’s User-Agent

Passing a header through headers replaces the profile’s matching header and leaves the rest of the fingerprint intact, so read the value first when you want to build on it.

import { fetch, getEmulationHeaders } from 'wreq-js';

const userAgent = getEmulationHeaders('firefox_147', 'windows').get('user-agent');

const response = await fetch('https://example.com', {
  browser: 'firefox_147',
  os: 'windows',
  headers: { 'X-Forwarded-User-Agent': userAgent ?? '' },
});

Headers

The Headers class for working with HTTP headers.

Constructor

declare class Headers {
  constructor(init?: HeadersInit);
}

Methods

append(name, value): add a header value
delete(name): remove a header
get(name): get a header value
has(name): check if header exists
set(name, value): set a header value
entries(): iterate over header entries
keys(): iterate over header names
values(): iterate over header values

Example

import { fetch, Headers } from 'wreq-js';

const headers = new Headers();
headers.set('Authorization', 'Bearer token');
headers.set('Content-Type', 'application/json');

const response = await fetch('https://api.example.com', {
  browser: 'chrome_142',
  headers,
});

Response

The Response class representing HTTP responses.

Properties

status: HTTP status code
statusText: HTTP status text
headers: response headers
ok: true if status is 200-299
url: final URL after redirects
redirected: true if the response is the result of a redirect
body: ReadableStream<Uint8Array> or null
bodyUsed: true if body has been read
contentLength: content length from headers, or null
cookies: parsed response cookies as Record<string, string | string[]>

Methods

json(): parse body as JSON
text(): get body as string
textStream(): get body as a ReadableStream<string> of UTF-8 decoded chunks
arrayBuffer(): get body as ArrayBuffer
bytes(): get body as Uint8Array
blob(): get body as Blob
formData(): parse body as FormData
clone(): clone the response

API Reference

Utilities

getProfiles()

Signature

Returns

Example

Using a random profile

getOperatingSystems()

Signature

Returns

Example

Combining browser and OS

resolveProfile()

Signature

Returns

Example

randomProfile()

Signature

Returns

Example

getEmulationHeaders()

Signature

Returns

Example

Reusing a profile’s User-Agent

Headers

Constructor

Methods

Example

Response

Properties

Methods

​getProfiles()

​Signature

​Returns

​Example

​Using a random profile

​getOperatingSystems()

​Signature

​Returns

​Example

​Combining browser and OS

​resolveProfile()

​Signature

​Returns

​Example

​randomProfile()

​Signature

​Returns

​Example

​getEmulationHeaders()

​Signature

​Returns

​Example

​Reusing a profile’s User-Agent

​Headers

​Constructor

​Methods

​Example

​Response

​Properties

​Methods

getProfiles()

Signature

Returns

Example

Using a random profile

getOperatingSystems()

Signature

Returns

Example

Combining browser and OS

resolveProfile()

Signature

Returns

Example

randomProfile()

Signature

Returns

Example

getEmulationHeaders()

Signature

Returns

Example

Reusing a profile’s User-Agent

Headers

Constructor

Methods

Example

Response

Properties

Methods